Fluorocarbon, oxygenated and non-oxygenated lubricant, and compatibilizer composition, and method for replacing refrigeration composition in a refrigeration system

ABSTRACT

The present invention relates to refrigerant compositions comprising a fluorocarbon, an oxygenated lubricant, a non-oxygenated lubricant, and a compatibilizer. The present invention further relates to methods for replacing a chlorofluorocarbon or hydrochlorofluorocarbon and a non-oxygenated lubricant composition with a fluorocarbon and an oxygenated lubricant composition in a compression refrigeration system without flushing residual non-oxygenated lubricant from the system

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of prior U. S. patentapplication Ser. No. 10/460037, filed Jun. 9, 2003.

FIELD OF THE INVENTION

[0002] The present invention relates to refrigerant compositionscomprising a fluorocarbon, an oxygenated lubricant, a non-oxygenatedlubricant, and a compatibilizer. The present invention further relatesto methods for replacing a chlorofluorocarbon or hydrochlorofluorocarbonand a non-oxygenated lubricant composition with a fluorocarbon andoxygenated lubricant composition in a compression refrigeration systemwithout flushing residual non-oxygenated lubricant from the system.

BACKGROUND

[0003] Over the course of the last twenty (20) years it has been debatedwhether the release of chlorofluorocarbons (CFCs) into the atmospherehas effected the stratospheric ozone layer. As a result of this debateand international treaties, the refrigeration and air-conditioningindustries have been weaning themselves from the use of CFCs andhydrochlorofluorocarbons (HCFCs). Presently, the industries aretransitioning towards the use of hydrofluorocarbons (HFCs) having zeroozone depletion potential, as well as other fluorocarbon refrigerantsnot containing chlorine. Notably, this transition to HFCs necessitatedthe advent of a new class of lubricants because of the immiscibility ofnon-oxygenated conventional lubricants, such as mineral oil,alkylbenzene, and poly-α-olefin, with HFC refrigerants.

[0004] As a result of the transition from CFC and HCFC to HFC and otherfluorocarbon refrigerants in vapor compression refrigeration systems,many systems currently installed in the field will require retrofit.However, the non-oxygenated conventional compressor lubricants used withCFCs and HCFCs are not miscible with HFC refrigerants underrefrigeration system operating conditions. While attempts have been madeto use non-oxygenated and relatively non-polar conventional lubricantswith relatively polar hydrofluorocarbon refrigerants, the lack ofsolubility of the HFC refrigerant in the non-oxygenated conventionallubricant generally results in a highly viscous, immiscible,non-oxygenated lubricant remainder or coating in non-compressor zones ofa refrigeration system if non-oxygenated lubricant is not thoroughlyflushed from the system during retrofit. The presence of residualnon-oxygenated lubricant in a vapor compression system can form a secondphase, particularly in the evaporator and condenser, which can interferewith heat transfer and cause reduction in the energy efficiency andcapacity of the system. Therefore, most compression refrigerationsystems require costly and time-consuming flushing to removenon-oxygenated conventional lubricants and replace them with lubricantswhich are miscible with HFCs, such as polyol ester (POE), polyalkyleneglycol (PAG) and polyvinyl ether (PVE) lubricants.

[0005] Accordingly, there exists a need and an opportunity to resolvethis solubility problem so that the refrigeration industry may retrofitsystems without costly and time-consuming flushing to entirely removeconventional lubricants. The present invention satisfies this need ofthe industry.

SUMMARY

[0006] The present invention is directed to refrigerant and lubricantcompositions containing a compatibilizer that satisfies therefrigeration and air-conditioning industry's problem of insolubilitybetween non-oxygenated conventional compression refrigerationlubricants, hydrofluorocarbon and oxygenated lubricant refrigerantcompositions.

[0007] The present invention includes refrigerant compositionscomprising: (a) a fluorocarbon; (b) an oxygenated lubricant selectedfrom the group consisting of polyol esters, polyalkylene glycols andpolyvinyl ethers; (c) a non-oxygenated lubricant selected from the groupconsisting of paraffins, napthenes, aromatics and poly-α-olefins; and(d) a compatibilizer. The compatibilizer increases the solubility ofresidual non-oxygenated lubricant in fluorocarbon and oxygenatedlubricant refrigerant compositions in the coldest portions of acompression refrigeration apparatus and eliminates the need for flushingresidual non-oxygenated lubricant during retrofit.

[0008] The present invention is also directed to methods for replacing afirst refrigerant composition comprising a chlorofluorocarbon and/orhydrochlorofluorocarbon and a non-oxygenated lubricant with a secondrefrigerant composition comprising a fluorocarbon and an oxygenatedlubricant in a compression refrigeration system without removingresidual non-oxygenated lubricant from said system. The method comprises(a) removing essentially all of the first composition from the system;(b) leaving residual non-oxygenated lubricant in said system followingsaid removal of the first composition; and (c) adding to said systemsaid second composition and a compatibilizer. The aforementionednon-oxygenated lubricant is selected from the group consisting ofparaffins, napthenes, aromatics and poly-α-olefins; and said oxygenatedlubricant is selected from the group consisting of polyol esters,polyalkylene glycols and polyvinyl ethers.

[0009] The present invention is further directed to methods fordissolving non-oxygenated lubricant in a fluorocarbon and oxygenatedlubricant refrigerant composition within a compression refrigerationsystem. The method involves adding a compatibilizer to a systemcontaining a composition comprising a non-oxygenated lubricant,fluorocarbon and oxygenated lubricant. The non-oxygenated lubricant isselected from the group consisting of paraffins, napthenes, aromaticsand poly-α-olefins and the oxygenated lubricant is selected from thegroup consisting of polyol esters, polyalkylene glycols and polyvinylethers.

DETAILED DESCRIPTION

[0010] The present inventor discovered that using an effective amount ofthe present compatibilizers in a compression refrigeration systemcontaining residual non-oxygenated conventional lubricant followingretrofit, results in efficient solubilization of the residualnon-oxygenated conventional lubricant in the fluorocarbon and oxygenatedlubricant composition. The compatibilizers travel throughout acompression refrigeration system mixed with refrigerant and lubricantthat escapes the compressor. The use of compatibilizers causes anincrease in solubility of residual non-oxygenated conventional lubricantin the fluorocarbon and oxygenated lubricant composition. The increasein solubility promotes the return of the non-oxygenated lubricant fromthe evaporator to the compressor and dilutes the residual non-oxygenatedlubricant in the fluorocarbon and an oxygenated lubricant composition.

[0011] By controlling the ratio of carbon to polar groups (e.g. ether,carbonyl, nitrile, halogen) in the compatibilizer, the inventordiscovered that the polar-group-containing compatibilizer couldsurprisingly increase the solubility of residual non-oxygenatedconventional lubricant in a hydrofluorocarbon and oxygenated lubricantcomposition. Controlling the aforesaid ratio leads to the non-oxygenatedlubricant remaining miscible with the hydrofluorocarbon and oxygenatedlubricant composition in the coldest sections of compressionrefrigeration apparatus. Without wishing to be bound by theory, thepolar functional groups in the present compatibilizers are attracted tothe relatively polar hydrofluorocarbon and oxygenated lubricant whilethe hydrocarbon portion of the compatibilizer is miscible with thenon-oxygenated lubricant. Use of the present compatibilizers causes anincrease in the solubility of residual non-oxygenated conventionallubricant in the fluorocarbon and oxygenated lubricant composition, andefficient return of all lubricant from a non-compressor zone to acompressor zone in a compression refrigeration system. Reducing theamount of all lubricants in the evaporator zone also improves heattransfer of the refrigerant and refrigerating capacity and efficiency ofa system. The present compatibilizers allow for retrofit of acompression refrigeration system to a relatively polar hydrofluorocarbon(or other fluorocarbon refrigerant) and an oxygenated lubricantcompositions without flushing residual non-oxygenated conventionallubricant.

[0012] The increased solubility of residual non-oxygenated lubricant influorocarbon and oxygenated lubricant compositions further allows liquidrefrigerant to dissolve and carry residual non-oxygenated lubricant outof the condenser. The above increase in solubility improves lubricantreturn and heat transfer in the condenser. It also improves capacity andefficiency of the refrigeration system.

[0013] In the present refrigerant composition comprising lubricant andcompatibilizer, from about 0.1 to about 50 weight percent, preferablyfrom about 1 to about 30 weight percent, and most preferably from about5 to about 15 weight percent of the combined lubricant andcompatibilizer composition is compatibilizer. Compatibilizer may becharged to a compression refrigeration system in a number of ways, forexample: by direct injection of neat compatibilizer into a system;premixed with oxygenated lubricant; premixed with hydrofluorocarbonrefrigerant; and/or preloaded into a filter dryer or other systemcomponent. An effective amount of compatibilizer in the presentcompositions and methods leads to residual non-oxygenated lubricant,resulting from system retrofit without flushing, becoming solubilized inthe hydrofluorocarbon and oxygenated lubricant composition to the extentthat adequate return of all lubricant in a compression refrigerationsystem from non-compressor zones (e.g. evaporator or condenser) to thecompressor zone is obtained.

[0014] Chlorofluorocarbon refrigerants of the present invention arethose conventional refrigerants consisting essentially of the elementschlorine, fluorine and carbon, for example, CFC-11 (CFCl₃) and CFC-12(CF₂Cl₂). Hydrochlorofluorocarbon refrigerants of the present inventionare interim, alternate CFC-replacement refrigerants consistingessentially of the elements hydrogen, chlorine, fluorine and carbon. Forexample, HCFC-22 (CHClF₂) and HCFC-124 (CHClFCF₃). Additionally,mixtures of chlorofluorocarbons and/or hydrochlorofluorocarbons, e.g.CFC-115 (CF₃CF₂Cl)/HCFC-22 (CHF₂Cl) (known by the ASHRAE designationR-502), are included as refrigerants in the first compositions of thepresent invention.

[0015] Fluorocarbon refrigerants of the present invention contain atleast one carbon atom and one fluorine atom. Of particular utility arefluorocarbons having 1-6 carbon atoms containing at least one fluorineatom, optionally containing oxygen atoms, and having a normal boilingpoint of from −90° C. to 80° C. These fluorocarbons may be representedby the general formula C_(x)F_(2x+2−y)H_(y)O_(z), wherein x is 1-6, y is0-9, and z is 0-2. Preferred of the fluorocarbons are those in which xis 1-6, y is 1-5 and z is 0-1. Fluorocarbons are commercial productsavailable from a number of sources such as E. I. du Pont de Nemours &Co., Fluoroproducts, Wilmington, Del., 19898, U.S.A., and additionallyby synthetic processes disclosed in art such as Chemistry of OrganicFluorine Compounds, edited by Milos Hudlicky, published by The MacMillanCompany, New York, N.Y., 1962. Representative fluorocarbons include:CHF₃ (HFC-23), CH₂F₂ (HFC-32), CH₃F (HFC-41), CF₃CF₃ (PFC-116), CHF₂CF₃(HFC-125), CHF₂CHF₂ (HFC-134), CH₂FCF₃ (HFC-134a), CHF₂CH₂F (HFC143),CF₃CH₃ (HFC-143a), CHF₂CH₃ (HFC-152a), CF₃CF₂CF₃ (PFC-218), CHF₂CF₂CF₃(HFC-227ca, CF₃CFHCF₃ (HFC-227ea), CHF₂CF₂CHF₂ (HFC-236ca), CH₂FCF₂CF₃(HFC-236cb), CHF₂CHFCF₃ (HFC-236ea), CF₃CH₂CF₃ (HFC-236fa), CH₂FCF₂CHF₂(HFC-245ca), CH₃CF₂CF₃ (HFC-245cb), CHF₂CHFCHF₂ (HFC-245ea), CH₂FCHFCF₃(HFC-245eb), CHF₂CH₂CF₃ (HFC-245fa), CH₂FCF₂CH₂F (HFC-254ca), CH₂CF₂CHF₂(HFC-254cb), CH₂FCHFCHF₂ (HFC-254ea), CH₃CHFCF₃ (HFC-254eb), CHF₂CH₂CHF₂(HFC-254fa), CH₂FCH₂CF₃ (HFC-254fb), CH₃CF₂CH₃ (HFC-272ca), CH₃CHFCH₂F(HFC-272ea), CH₂FCH₂CH₂F (HFC-272fa), CH₃CH₂CF₂H (HFC-272fb), CH₃CHFCH₃(HFC-281 ea), CH₃CH₂CH₂F (HFC-281 fa), cyclo-C4F8 (PFC-C318),CHF₂CF₂CF₂CF₂H (HFC-338pcc), CF₃CHFCHFCF₂CF₃ (HFC-43-10mee), C₄F₉OCH₃,and C₄F₉OC₂H₅.

[0016] The present invention is particularly useful with azeotropic andazeotrope-like fluorocarbon refrigerant compositions, such as,HFC-125/HFC-143a/HFC-134a (known by the ASHRAE designation R-404A),HFC-32/HFC-125/HFC-134a (known by ASHRAE designations R-407A, R-407B,and R-407C), HFC-32/HFC-125 (R-410A), and HFC-125/HFC-143a (known by theASHRAE designation R-507).

[0017] The fluorocarbons of the present invention may optionally furthercomprise up to 10 weight percent of dimethyl ether, or at least one C₃to C₅ hydrocarbon, e.g., propane, propylene, cyclopropane, n-butane,i-butane, n-pentane, cyclopentane, isopentane (2-methylbutane) andneopentane (2,2-dimethylpropane). Examples of fluorocarbons containingsuch C₃ to C₅ hydrocarbons are azeotrope-like compositions ofHFC-125/HFC-134a/n-butane (known by the ASHRAE designation R-417A).

[0018] Lubricants of the present invention are selected by considering agiven compressor's requirements and the environment in which thelubricant will be exposed. Lubricants of the present inventionpreferably have a kinematic viscosity of at least about 15 centistokesat 40° C.

[0019] Non-oxygenated conventional lubricants of the present inventionare those conventionally used in compression refrigeration apparatusutilizing chlorofluorocarbon and hydrochlorofluorocarbon refrigerants.Such lubricants and their properties are discussed in the 1990 ASHRAEHandbook, Refrigeration Systems and Applications, chapter 8, titled“Lubricants in Refrigeration Systems”, pages 8.1 through 8.21, hereinincorporated by reference. Non-oxygenated lubricants of the presentinvention comprise those commonly known as “mineral oils” in the fieldof compression refrigeration lubrication. Mineral oils compriseparaffins (i.e. straight chain and branched-carbon-chain, saturatedhydrocarbons), naphthenes (i.e. cyclic paraffins) and aromatics (i.e.unsaturated, cyclic hydrocarbons containing one or more ringscharacterized by alternating double bonds). Non-oxygenated lubricants ofthe present invention further comprise those commonly known as“synthetic oils” in the field of compression refrigeration lubrication.Synthetic oils comprise alkylaryls (i.e. linear and branched alkylalkylbenzenes), synthetic paraffins and napthenes, andpoly(alpha-olefins). Representative non-oxygenated lubricants of thepresent invention are the commercially available BVM 100 N (paraffinicmineral oil sold by BVA Oils), Suniso® 3GS (napthenic mineral oil soldby Crompton Co.), Sontex® 372LT (napthenic mineral oil sold byPennzoil), Calumet® RO-30 (napthenic mineral oil sold by CalumentLubricants), Zerol® 75 and Zerol® 150 (linear alkylbenzenes sold byShrieve Chemicals) and HAB 22 (branched alkylbenzene sold by NipponOil).

[0020] Oxygenated lubricants of the present invention are those whichhave been designed for use with hydrofluorocarbon refrigerants and aremiscible with hydrofluorocarbons under compression refrigeration systemoperating conditions. Such lubricants and their properties are discussedin “Refrigeration lubricants—current practice and future development” byG. Short, T. Rajewski and J. Oberle of CPI Engineering Services,Midland, Mich., U.S.A. in Proceedings of the International RefrigerationConference at Purdue, 6th, West Lafayette, Ind., Jul. 23-26, 1996(1996), 265-271, editors J. Braun and E. Groll and published by PurdueUniversity, West Lafayette, Ind. Oxygenated lubricants include, but arenot limited to, polyol esters, polyalkylene glycols, and polyvinylethers.

[0021] Compatibilizers of the present invention comprise polyoxyalkyleneglycol ethers represented by the formula R¹[(OR²)_(x)OR³]_(y), wherein:x is selected from integers from 1-3; y is selected from integers from1-4; R¹ is selected from hydrogen and aliphatic hydrocarbon radicalshaving 1 to 6 carbon atoms and y bonding sites; R² is selected fromaliphatic hydrocarbylene radicals having from 2 to 4 carbon atoms; R³ isselected from hydrogen and aliphatic and alicyclic hydrocarbon radicalshaving from 1 to 6 carbon atoms; at least one of R¹ and R³ is saidhydrocarbon radical; and wherein said polyoxyalkylene glycol ethers havea molecular weight of from about 100 to about 300 atomic mass units anda carbon to oxygen ratio of from about 2.3 to about 5.0. In the presentpolyoxyalkylene glycol ether compatibilizers represented byR¹[(OR²)_(x)OR³]_(y): x is preferably 1-2; y is preferably 1; R¹ and R³are preferably independently selected from hydrogen and aliphatichydrocarbon radicals having 1 to 4 carbon atoms; R² is preferablyselected from aliphatic hydrocarbylene radicals having from 2 or 3carbon atoms, most preferably 3 carbon atoms; the polyoxyalkylene glycolether molecular weight is preferably from about 100 to about 250 atomicmass units, most preferably from about 125 to about 250 atomic massunits; and the polyoxyalkylene glycol ether carbon to oxygen ratio ispreferably from about 2.5 to 4.0, most preferably from about 2.7 toabout 3.5. The R¹ and R³ hydrocarbon radicals having 1 to 6 carbon atomsmay be linear, branched or cyclic. Representative R¹ and R³ hydrocarbonradicals include methyl, ethyl, propyl, isopropyl, butyl, isobutyl,sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl,cyclopentyl, and cyclohexyl. Where free hydroxyl radicals on the presentpolyoxyalkylene glycol ether compatibilizers may be incompatible withcertain compression refrigeration apparatus materials of construction(e.g. Mylar®), R¹ and R³ are preferably aliphatic hydrocarbon radicalshaving 1 to 4 carbon atoms, most preferably 1 carbon atom. The R²aliphatic hydrocarbylene radicals having from 2 to 4 carbon atoms formrepeating oxyalkylene radicals—(OR²)_(x)—that include oxyethyleneradicals, oxypropylene radicals, and oxybutylene radicals. Theoxyalkylene radical comprising R² in one polyoxyalkylene glycol ethercompatibilizer molecule may be the same or one molecule may containdifferent R² oxyalkylene groups. The present polyoxyalkylene glycolether compatibilizers preferably comprise at least one oxypropyleneradical. Where R¹ is an aliphatic or alicyclic hydrocarbon radicalhaving 1 to 6 carbon atoms and y bonding sites, the radical may belinear, branched or cyclic. Representative R¹ aliphatic hydrocarbonradicals having two bonding sites include, for example, an ethyleneradical, a propylene radical, a butylene radical, a pentylene radical, ahexylene radical, a cyclopentylene radical and a cyclohexylene radical.Representative R¹ aliphatic hydrocarbon radicals having three or fourbonding sites include residues derived from polyalcohols, such astrimethylolpropane, glycerin, pentaerythritol,1,2,3-trihydroxycyclohexane and 1,3,5-trihydroxycyclohexane, by removingtheir hydroxyl radicals. Representative polyoxyalkylene glycol ethercompatibilizers include: CH₃OCH₂CH(CH₃)O(H or CH₃) (propylene glycolmethyl (or dimethyl) ether), CH₃O[CH₂CH(CH₃)O]₂(H or CH₃) (dipropyleneglycol methyl (or dimethyl) ether), CH₃O[CH₂CH(CH₃)O]₃(H or CH₃)(tripropylene glycol methyl (or dimethyl) ether), C₂H₅OCH₂CH(CH₃)O(H orC₂H₅) (propylene glycol ethyl (or diethyl) ether), C₂H₅O[CH₂CH(CH₃)O]₂(Hor C₂H₅) (dipropylene glycol ethyl (or diethyl) ether),C₂H₅O[CH₂CH(CH₃)O]₃(H or C₂H₅) (tripropylene glycol ethyl (or diethyl)ether), C₃H₇OCH₂CH(CH₃)O(H or C₃H₇) (propylene glycol n-propyl (ordi-n-propyl) ether), C₃H₇O[CH₂CH(CH₃)O]₂(H or C₃H₇) (dipropylene glycoln-propyl (or di-n-propyl) ether) , C₃H₇O[CH₂CH(CH₃)O]₃(H or C₃H₇)(tripropylene glycol n-propyl (or di-n-propyl) ether), C₄H₉OCH₂CH(CH₃)OH(propylene glycol n-butyl ether), C₄H₉O[CH₂CH(CH₃)O]₂(H or C₄H₉)(dipropylene glycol n-butyl (or di-n-butyl) ether),C₄H₉O[CH₂CH(CH₃)O]₃(H or C₄H₉) (tripropylene glycol n-butyl (ordi-n-butyl) ether), (CH₃)₃COCH₂CH(CH₃)OH (propylene glycol t-butylether), (CH₃)₃CO[CH₂CH(CH₃)O]₂(H or (CH₃)₃) (dipropylene glycol t-butyl(or di-t-butyl) ether), (CH₃)₃CO[CH₂CH(CH₃)O]₃(H or (CH₃)₃)(tripropylene glycol t-butyl (or di-t-butyl) ether), C₅H₁₁OCH₂CH(CH₃)OH(propylene glycol n-pentyl ether), C₄H₉OCH₂CH(C₂H₅)OH (butylene glycoln-butyl ether), C₄H₉O[CH₂CH(C₂H₅)O]₂H (dibutylene glycol n-butyl ether),trimethylolpropane tri-n-butyl ether (C₂H₅C(CH₂O(CH₂)₃CH₃)₃) andtrimethylolpropane di-n-butyl ether (C₂H₅C(CH₂OC(CH₂)₃CH₃)₂CH₂OH)

[0022] Compatibilizers of the present invention further comprise amidesrepresented by the formulae R¹CONR²R³ and cyclo-[R⁴CON(R⁵)—], whereinR¹, R², R³ and R⁵ are independently selected from aliphatic andalicyclic hydrocarbon radicals having from 1 to 12 carbon atoms, and atmost one aromatic radical having from 6 to 12 carbon atoms; R⁴ isselected from aliphatic hydrocarbylene radicals having from 3 to 12carbon atoms; and wherein said amides have a molecular weight of fromabout 120 to about 300 atomic mass units and a carbon to oxygen ratio offrom about 7 to about 20. The molecular weight of said amides ispreferably from about 160 to about 250 atomic mass units. The carbon tooxygen ratio in said amides is preferably from about 7 to about 16, andmost preferably from about 10 to about 14. R¹, R², R³ and R⁵ mayoptionally include substituted radicals, that is, radicals containingnon-hydrocarbon substituents selected from halogens (e.g., fluorine,chlorine) and alkoxides (e.g. methoxy). R¹, R², R³ and R⁵ may optionallyinclude heteroatom-substituted radicals, that is, radicals, whichcontain the atoms nitrogen (aza-), oxygen (oxa-) or sulfur (thia-) in aradical chain otherwise composed of carbon atoms. In general, no morethan three non-hydrocarbon substituents and heteroatoms, and preferablyno more than one, will be present for each 10 carbon atoms in R¹⁻³ andR⁵, and the presence of any such non-hydrocarbon substituents andheteroatoms must be considered in applying the aforementioned ratio ofcarbon to oxygen and molecular weight limitations. Preferred amidecompatibilizers consist of carbon, hydrogen, nitrogen and oxygen.Representative R¹, R², R³ and R⁵ aliphatic and alicyclic hydrocarbonradicals include methyl, ethyl, propyl, isopropyl, butyl, isobutyl,sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl,cyclopentyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyland their configurational isomers. Representative R¹, R², R³ and R⁵aromatic radicals include phenyl, cumenyl, mesityl, tolyl, xylyl,benzyl, phenethyl, thienyl, furyl, pyrrolyl and pyridyl. A preferredembodiment of amide compatibilizers are those wherein R⁴ in theaforementioned formula cyclo-[R⁴CON(R⁵)—] may be represented by thehydrocarbylene radical (CR⁶R⁷)_(n), in other words, the formula:cyclo-[(CR⁶R⁷)_(n)CON(R⁵)—] wherein: the previously-stated values for(a) ratio of carbon to oxygen and (b) molecular weight apply; n is aninteger from 3 to 5; R⁵ is a saturated hydrocarbon radical containing 1to 12 carbon atoms; R⁶ and R⁷ are independently selected (for each n) bythe rules previously offered defining R¹⁻³. In the lactams representedby the formula: cyclo-[(CR⁶R⁷)_(n)CON(R⁵)—], all R⁶ and R⁷ arepreferably hydrogen, or contain a single saturated hydrocarbon radicalamong the n methylene units, and R⁵ is a saturated hydrocarbon radicalcontaining 3 to 12 carbon atoms. For example, 1-(saturated hydrocarbonradical)-5-methylpyrrolidin-2-ones. Representative amide compatibilizersinclude: 1-octylpyrrolidin-2-one, 1-decylpyrrolidin-2-one,1-octyl-5-methylpyrrolidin-2-one, 1-butylcaprolactam,1-isobutylcaprolactam, 1-cyclohexylpyrrolidin-2-one,1-cyclohexyl-5-methylpyrrolidin-2-one, 1-butyl-5-methylpiperid-2-one,1-pentyl-5-methylpiperid-2-one, 1-hexylcaprolactam,1-hexyl-5-methylpyrrolidin-2-one, 1-heptyl-5-methylpyrrolidin-2-one,1-nonyl-5-methylpyrrolidin-2-one, 1-undecyl-5-methylpyrrolidin-2-one,1-dodecyl-5-methylpyrrolidin-2-one, 5-methyl-1-pentylpiperid-2-one,1,3-dimethylpiperid-2-one, 1-methylcaprolactam,1-butyl-pyrrolidin-2-one, 1,5-dimethylpiperid-2-one,1-decyl-5-methylpyrrolidin-2-one, 1-dodecylpyrrolid-2-one,N,N-dibutylformamide and N,N-diisopropylacetamide.

[0023] Compatibilizers of the present invention further comprise ketonesrepresented by the formula R¹COR², wherein R¹ and R² are independentlyselected from aliphatic, alicyclic and aryl hydrocarbon radicals havingfrom 1 to 12 carbon atoms, and wherein said ketones have a molecularweight of from about 70 to about 300 atomic mass units and a carbon tooxygen ratio of from about 4 to about 13. R¹ and R² in said ketones arepreferably independently selected from aliphatic and alicyclichydrocarbon radicals having 1 to 9 carbon atoms. The molecular weight ofsaid ketones is preferably from about 100 to 200 atomic mass units. Thecarbon to oxygen ratio in said ketones is preferably from about 7 toabout 10. R¹ and R² may together form a hydrocarbylene radical connectedand forming a five, six, or seven-membered ring cyclic ketone, forexample, cyclopentanone, cyclohexanone, and cycloheptanone. R¹ and R²may optionally include substituted hydrocarbon radicals, that is,radicals containing non-hydrocarbon substituents selected from halogens(e.g., fluorine, chlorine) and alkoxides (e.g. methoxy). R¹ and R² mayoptionally include heteroatom-substituted hydrocarbon radicals, that is,radicals, which contain the atoms nitrogen (aza-), oxygen (keto-, oxa-)or sulfur (thia-) in a radical chain otherwise composed of carbon atoms.In general, no more than three non-hydrocarbon substituents andheteroatoms, and preferably no more than one, will be present for each10 carbon atoms in R¹ and R², and the presence of any suchnon-hydrocarbon substituents and heteroatoms must be considered inapplying the aforementioned ratio of carbon to oxygen and molecularweight limitations. Representative R¹ and R² aliphatic, alicyclic andaryl hydrocarbon radicals in the general formula R¹COR² include methyl,ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, cyclohexyl,heptyl, octyl, nonyl, decyl, undecyl, dodecyl and their configurationalisomers, as well as phenyl, benzyl, cumenyl, mesityl, tolyl, xylyl andphenethyl. Representative ketone compatibilizers include: 2-butanone,2-pentanone, acetophenone, butyrophenone, hexanophenone, cyclohexanone,cycloheptanone, 2-heptanone, 3-heptanone, 5-methyl-2-hexanone,2-octanone, 3-octanone, diisobutyl ketone, 4-ethylcyclohexanone,2-nonanone, 5-nonanone, 2-decanone, 4-decanone, 2-decalone,2-tridecanone, dihexyl ketone and dicyclohexyl ketone.

[0024] Compatibilizers of the present invention further comprisenitriles represented by the formula R¹CN, wherein R¹ is selected fromaliphatic, alicyclic or aryl hydrocarbon radicals having from 5 to 12carbon atoms, and wherein said nitriles have a molecular weight of fromabout 90 to about 200 atomic mass units and a carbon to nitrogen ratioof from about 6 to about 12. R¹ in said nitrile compatibilizers ispreferably selected from aliphatic and alicyclic hydrocarbon radicalshaving 8 to 10 carbon atoms. The molecular weight of said nitrilecompatibilizers is preferably from about 120 to about 140 atomic massunits. The carbon to nitrogen ratio in said nitrile compatibilizers ispreferably from about 8 to about 9. R¹ may optionally includesubstituted hydrocarbon radicals, that is, radicals containingnon-hydrocarbon substituents selected from halogens (e.g., fluorine,chlorine) and alkoxides (e.g. methoxy). R¹ may optionally includeheteroatom-substituted hydrocarbon radicals, that is, radicals, whichcontain the atoms nitrogen (aza-), oxygen (keto-, oxa-) or sulfur(thia-) in a radical chain otherwise composed of carbon atoms. Ingeneral, no more than three non-hydrocarbon substituents andheteroatoms, and preferably no more than one, will be present for each10 carbon atoms in R¹, and the presence of any such non-hydrocarbonsubstituents and heteroatoms must be considered in applying theaforementioned ratio of carbon to nitrogen and molecular weightlimitations. Representative R¹ and R² aliphatic, alicyclic and arylhydrocarbon radicals in the general formula R¹CN include pentyl,isopentyl, neopentyl, tert-pentyl, cyclopentyl, cyclohexyl, heptyl,octyl, nonyl, decyl, undecyl, dodecyl and their configurational isomers,as well as phenyl, benzyl, cumenyl, mesityl, tolyl, xylyl and phenethyl.Representative nitrile compatibilizers include: 1-cyanopentane,2,2-dimethyl-4-cyanopentane, 1-cyanohexane, 1-cyanoheptane,1-cyanooctane, 2-cyanooctane, 1-cyanononane, 1-cyanodecane,2-cyanodecane, 1-cyanoundecane and 1-cyanododecane. Nitrilecompatibilizers are especially useful in compatibilizing HFCrefrigerants with aromatic and alkylaryl lubricants.

[0025] Compatibilizers of the present invention further comprisechlorocarbons represented by the formula RCl_(x), wherein; x is selectedfrom the integers 1 or 2; R is selected from aliphatic and alicyclichydrocarbon radicals having 1 to 12 carbon atoms; and wherein saidchlorocarbons have a molecular weight of from about 100 to about 200atomic mass units and carbon to chlorine ratio from about 2 to about 10.The molecular weight of said chlorocarbon compatibilizers is preferablyfrom about 120 to 150 atomic mass units. The carbon to chlorine ratio insaid chlorocarbon compatibilizers is preferably from about 6 to about 7.Representative R aliphatic and alicyclic hydrocarbon radicals in thegeneral formula RCl_(x) include methyl, ethyl, propyl, isopropyl, butyl,isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl,tert-pentyl, cyclopentyl, cyclohexyl, heptyl, octyl, nonyl, decyl,undecyl, dodecyl and their configurational isomers. Representativechlorocarbon compatibilizers include: 3-(chloromethyl)pentane,3-chloro-3-methylpentane, 1-chlorohexane, 1,6-dichlorohexane,1-chloroheptane, 1-chlorooctane, 1-chlorononane, 1-chlorodecane, and1,1,1-trichlorodecane.

[0026] Compatibilizers of the present invention further comprise arylethers represented by the formula R¹OR², wherein: R¹ is selected fromaryl hydrocarbon radicals having from 6 to 12 carbon atoms; R² isselected from aliphatic hydrocarbon radicals having from 1 to 4 carbonatoms; and wherein said aryl ethers have a molecular weight of fromabout 100 to about 150 atomic mass units and a carbon to oxygen ratio offrom about 4 to about 20. The carbon to oxygen ratio in said aryl ethercompatibilizers is preferably from about 7 to about 10. RepresentativeR¹ aryl radicals in the general formula R¹OR² include phenyl, biphenyl,cumenyl, mesityl, tolyl, xylyl, naphthyl and pyridyl. Representative R²aliphatic hydrocarbon radicals in the general formula R¹OR² includemethyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl andtert-butyl. Representative aromatic ether compatibilizers include:methyl phenyl ether (anisole), 1,3-dimethyoxybenzene, ethyl phenyl etherand butyl phenyl ether.

[0027] Compatibilizers of the present invention further comprise1,1,1-trifluoroalkanes represented by the general formula CF₃R¹ ,wherein R¹ is selected from aliphatic and alicyclic hydrocarbon radicalshaving from about 5 to about 15 carbon atoms, preferably primary,linear, saturated, alkyl radicals. Representative 1,1,1-trifluoroalkanecompatibilizers include: 1,1,1-trifluorohexane and1,1,1-trifluorododecane.

[0028] Compatibilizers of the present invention further comprisefluoroethers represented by the general formula R¹OCF₂CF₂H, wherein R¹is selected from aliphatic and alicyclic hydrocarbon radicals havingfrom about 5 to about 15 carbon atoms, preferably primary, linear,saturated, alkyl radicals. Representative fluoroether compatibilizersinclude: C₈H₁₇OCF₂CF₂H and C₆H₁₃OCF₂CF₂H.

[0029] Compatibilizers of the present invention comprise lactonesrepresented by formulas I, II, and III:

[0030] These lactones contain the functional group —CO₂— in a ring ofsix (I), or preferably five atoms (II), wherein for formulas I and II,R₁ through R₈ are independently selected from hydrogen, linear,branched, cyclic, bicyclic, saturated and unsaturated hydrocarbylradicals. Each R₁ though R₈ may be connected forming a ring with anotherR₁ through R₈. The lactone may have an exocyclic alkylidene group as informula III, wherein R₁ through R₆ are independently selected fromhydrogen, linear, branched, cyclic, bicyclic, saturated and unsaturatedhydrocarbyl radicals. Each R₁ though R₆ may be connected forming a ringwith another R₁ through R₆. The lactone compatibilizers of the presentinvention have a carbon to ester functional group carbonyl oxygen ratiofrom about 7 to about 15, preferred from about 9 to about 13, and mostpreferred from about 10 to about 12. Said lactone compatibilizers alsohave a molecular weight range of from about 100 to about 300 atomic massunits, preferred from about 150 to about 250 atomic mass units, and mostpreferred from about 175 to about 225 atomic mass units. Representativelactone compatibilizers include the compounds listed in the below table.Carbon to Ester Molecular Molecular Carbonyl Oxygen CompatibilizerMolecular Structure Formula Weight (amu) Ratio(E,Z)-3-ethylidene-5-methyl-di- hydro-furan-2-one

C₇H₁₀O₂ 126 7 (E,Z)-3-propylidene-5-meth- yl-dihydro-furan-2-one

C₈H₁₂O₂ 140 8 (E,Z)-3-butylidene-5-methyl-di- hydro-furan-2-one

C₉H₁₄O₂ 154 9 (E,Z)-3-pentylidene-5-meth- yl-dihydro-furan-2-one

C₁₀H₁₆O₂ 168 10 (E,Z)-3-Hexylidene-5-methyl-di- hydro-furan-2-one

C₁₁H₁₈O₂ 182 11 (E,Z)-3-Heptylidene-5-meth- yl-dihydro-furan-2-one

C₁₂H₂₀O₂ 196 12 (E,Z)-3-octylidene-5-methyl-di- hydro-furan-2-one

C₁₃H₂₂O₂ 210 13 (E,Z)-3-nonylidene-5-methyl-di- hydro-furan-2-one

C₁₄H₂₄O₂ 224 14 (E,Z)-3-decylidene-5-methyl-di- hydro-furan-2-one

C₁₅H₂₆O₂ 238 15 (E,Z)-3-cyclo- hexylmethylidene-5-meth-yl-dihydrofuran-2-one

C₁₂H₁₈O₂ 194 12 gamma-octalactone

C₈H₁₄O₂ 142 8 gamma-nonalactone

C₉H₁₆O₂ 156 9 gamma-decalactone

C₁₀H₁₈O₂ 170 10 gamma-undecalactone

C₁₁H₂₀O₂ 184 11 gamma-dodecalactone

C₁₂H₂₂O₂ 198 12 3-hexyldihydro-furan-2-one

C₁₀H₁₈O₂ 170 10 3-heptyldihydro-furan-2-one

C₁₁H₂₀O₂ 184 11 cis-3-ethyl-5-methyl-dihydro-fur- an-2-one

C₇H₁₂O₂ 128 7 cis-(3-propyl-5-methyl)-di- hydro-furan-2-one

C₈H₁₄O₂ 142 8 cis-(3-butyl-5-methyl)-di- hydro-furan-2-one

C₉H₁₆O₂ 156 9 cis-(3-pentyl-5-methyl)-di- hydro-furan-2-one

C₁₀H₁₈O₂ 170 10 cis-3-hexyl-5-methyl-dihydro-fur- an-2-one

C₁₁H₂₀O₂ 184 11 cis-3-heptyl-5-methyl-di- hydro-furan-2-one

C₁₂H₂₂O₂ 198 12 cis-3-octyl-5-methyl-dihydro-fur- an-2-one

C₁₃H₂₄O₂ 212 13 cis-3-(3,5,5-trimethylhexyl)-5-meth-yl-dihydro-furan-2-one

C₁₄H₂₆O₂ 226 14 5-methyl-5-hexyl-dihydro-fur- an-2-one

C₁₁H₂₀O₂ 184 11 5-methyl-5-octyl-dihydro-fur- an-2-one

C₁₃H₂₄O₂ 212 13 Hexahydro-isobenzofuran-1-one

C₈H₁₂O₂ 140 8 delta-decalactone

C₁₀H₁₈O₂ 170 10 delta-undecalactone

C₁₁H₂₀O₂ 184 11 delta-dodecalactone

C₁₂H₂₂O₂ 198 12 mixture of 4-hexyl-di- hydrofuran-2-one and 3-hex-yl-dihydro-furan-2-one (1.6:1 mole ratio, respectively)

C₁₀H₁₈O₂ 170 10

[0031] The lactone compatibilizers generally have a kinematic viscosityof less than about 7 centistokes at 40° C. For instance,gamma-undecalactone has kinematic viscosity of 5.4 centistokes andcis-(3-hexyl-5-methyl)-dihydrofuran-2-one has viscosity of 4.5centistokes at 40° C.

[0032] Lactone compatibilizers may be available commercially or preparedby methods as described in concurrently filed U. S. provisional patentapplication, attorney docket no. CL-2362 US PRV, entitled“cis-3,5-Disubstituted-dihydrofuran-2-ones and the Preparation and UseThereof”, for which inventors are P. J. Fagan and C. J. Brandenburg; andU.S. provisional patent application filed on Oct. 15, 2003, attorneydocket no. FL-1084 US PRV, entitled “Compositions Containing LactoneCompatibilizers”, for which inventors are B. H. Minor, P. J. Fagan andS. Shuey. The aforementioned patent applications are incorporated hereinby reference.

[0033] Compatibilizers of the present invention may comprise a singlecompatibilizer species or multiple compatibilizer species together inany proportion. For example, a compatibilizer may comprise a mixture ofcompounds from within a single compatibilizer species (e.g. a mixture ofpolyoxyalkylene glycol ethers) or a mixture of compounds chosen fromdifferent compatibilizer species (e.g. a mixture of a polyoxyalkyleneglycol ether with a ketone).

[0034] Compatibilizers of the present invention may optionally furthercomprise from about 0.5 to about 50 weight percent (based on totalamount of compatibilizer) of a linear or cyclic aliphatic or aromatichydrocarbon containing from 5 to 15 carbon atoms. Representativehydrocarbons include pentane, hexane, octane, nonane, decane, Isopar® H(a high purity C₁₁ to C₁₂ iso-paraffinic), Aromatic 150 (a C₉ to C₁₁aromatic), Aromatic 200 (a C₉ to C₁₅ aromatic) and Naptha 140. All ofthese hydrocarbons are sold by Exxon Chemical, USA.

[0035] Compatibilizers of the present invention may optionally furthercomprise a polymeric additive. The polymeric additive may be a randomcopolymer of fluorinated and non-fluorinated acrylates, wherein thepolymer comprises repeating units of at least one monomer represented bythe formulae CH₂═C(R¹ )CO₂R², CH₂═C(R³)C₆H₄R⁴, and CH₂═C(R⁵)C₆H₄XR⁶,wherein X is oxygen or sulfur; R¹, R³, and R⁵ are independently selectedfrom the group consisting of H and C₁-C₄ alkyl radicals; and R², R⁴, andR⁶ are independently selected from the group consisting ofcarbon-chain-based radicals containing C, and F, and may further containH, Cl, ether oxygen, or sulfur in the form of thioether, sulfoxide, orsulfone groups. Examples of such polymeric additives include thosedisclosed in U.S. Pat. No. 6,299,792, such as Zonyl® PHS sold by E. I.du Pont de Nemours & Co., Wilmington, Del., 19898, U.S.A. Zonyl® PHS isa random copolymer made by polymerizing 40 weight percentCH₂═C(CH₃)CO₂CH₂CH₂(CF₂CF₂)_(m)F (also referred to as Zonyl®fluoromethacrylate or ZFM) wherein m is from 1 to 12, primarily 2 to 8,and 60 weight percent lauryl methacrylate (CH₂═C(CH₃)CO₂(CH₂)₁₁CH₃, alsoreferred to as LMA).

[0036] Compatibilizers of the present invention may optionally furthercontain from about 0.01 to 30 weight percent (based on total amount ofcompatibilizer) of an additive which reduces the surface energy ofmetallic copper, aluminum, steel, or other metals found in heatexchangers in a way that reduces the adhesion of lubricants to themetal. Examples of metal surface energy reducing additives include thosedisclosed in WIPO PCT publication WO 96/7721, such as Zonyl® FSA, Zonyl®FSP, Zonyl® FSJ and Zonyl® FS62, all products of E. I. du Pont deNemours and Co. In practice, by reducing the adhesive forces between themetal and the lubricant (i.e. substituting for a compound more tightlybound to the metal), the lubricant circulates more freely through theheat exchangers and connecting tubing in an air conditioning orrefrigeration system, instead of remaining as a layer on the surface ofthe metal. This allows for the increase of heat transfer to the metaland allows efficient return of lubricant to the compressor.

[0037] Commonly used refrigeration system additives may optionally beadded, as desired, to compositions of the present invention in order toenhance lubricity and system stability. These additives are generallyknown within the field of refrigeration compressor lubrication such asanti wear agents, extreme pressure lubricants, corrosion and oxidationinhibitors, metal surface deactivators, free radical scavengers, foamingand antifoam control agents, leak detectants and the like. In general,these additives are present only in small amounts relative to theoverall lubricant composition. They are typically used at concentrationsof from less than about 0.1% to as much as about 3% of each additive.These additives are selected on the basis of the individual systemrequirements. Some typical examples of such additives may include, butare not limited to, lubrication enhancing additives, such as alkyl oraryl esters of phosphoric acid and of thiophosphates. These includemembers of the triaryl phosphate family of EP lubricity additives, suchas butylated triphenyl phosphates (BTPP), or other alkylated triarylphosphate esters, e.g. Syn-0-Ad 8478 from Akzo Chemicals, tricrecylphosphates and related compounds. Additionally, the metal dialkyldithiophosphates (e.g. zinc dialkyl dithiophosphate or ZDDP, Lubrizol1375) and other members of this family of chemicals may be used incompositions of the present invention. Other antiwear additives includenatural product oils and asymmetrical polyhydroxyl lubrication additivessuch as Synergol TMS (International Lubricants). Similarly, stabilizerssuch as anti oxidants, free radical scavengers, and water scavengers maybe employed. Compounds in this category can include, but are not limitedto, butylated hydroxy toluene (BHT) and epoxides.

[0038] Compatiblizers such as ketones may have an objectionable odor,which can be masked by addition of an odor masking agent or fragrance.Typical examples of odor masking agents or fragrances may includeEvergreen, Fresh Lemon, Cherry, Cinnamon, Peppermint, Floral or OrangePeel or sold by Intercontinental Fragrance, as well as d-limonene andpinene. Such odor masking agents may be used at concentrations of fromabout 0.001% to as much as about 15% by weight based on the combinedweight of odor masking agent and compatibilizer.

[0039] The present invention further comprises processes for producingrefrigeration comprising evaporating the present refrigerationcompositions in the vicinity of a body to be cooled, and processes forproducing heat comprising condensing hydrofluorocarbon refrigerant inthe presence of lubricant and compatibilizer in the presence of a bodyto be heated.

EXAMPLES

[0040] “POE 22” is used herein as an abbreviation for Mobil Oil productArctic EAL22, a polyol ester lubricant having a kinematic viscosity of22 centistokes at 40° C. Suniso® 3GS (herein abbreviated as “3GS”) is anapthenic mineral oil with a kinematic viscosity of 33 centistokes at40° C. sold by Crompton Corporation. Suniso® 4GS (herein abbreviated as“4GS”) is a napthenic mineral oil with a kinematic viscosity of 62centistokes at 40° C. sold by Crompton Corporation. “DMM” used herein isan abbreviation for dipropylene glycol dimethyl ether(CH₃O[CH₂CH(CH₃)O]₂CH₃). “OP” used herein is an abbreviation for 1-octylpyrrolidin-2-one (C₁₂H₂₃NO) “GUDL” used herein is an abbreviation forgamma-undecalactone. DMM, OP, and GUDL are all available from AldrichChemical Company (Milwaukee, Wis.).

Comparative Example 1

[0041] Compatibilizers of the present invention are placed in a suitablecontainer with hydrofluorocarbon refrigerant and lubricant and thetemperature lowered until two phases are observed by the naked eye(i.e., the phase separation temperature, also herein referred to as“PST”). The composition in the container 50 wt % HFC-134a(1,1,1,2-tetrafluoroethane) and 50 wt % lubricant/compatibilizercompositions as shown in the table below.

Example 1 Reduction in PST with Addition of Compatibilizers DMM, OP andGUDL to POE with Residual 3GS

[0042] POE22 3GS DMM OP GUDL PST wt % wt % wt % wt % wt % (C) CommentCOMPARATIVE DATA 50 −38 PST of POE 50 200 PST of 3GS 50 −111 PST of DMM50 −187 PST of OP 47.5 2.5 −26  5% Residual 3GS in POE 45 5 −14 10%Residual 3GS in POE EXAMPLE DATA 40.5 4.5 5 −24 10% Residual 3GS + 11%DMM in POE 40.5 4.5 5 −31 10% Residual 3GS + 11% OP in POE 42.3 4.7 3−25 10% Residual 3GS + 7% OP in POE 42.3 4.7 3 −23 10% Residual 3GS + 7%GUDL in POE 42.3 4.7 3 −20 10% Residual 3GS + 7% DMM in POE 42.8 2.2 5−42  5% Residual 3GS + 10% OP in POE 44.65 2.35 3 −36  5% Residual 3GS +6% OP in POE 44.65 2.35 3 −34  5% Residual 3 GS + 6% GUDL in POE 44.652.35 3 −31  5% Residual 3GS + 6% DMM in POE

[0043] Results show that addition of compatibilizers to a lubricantmixture containing POE and residual mineral oil lowers the phaseseparation temperature and thereby improves miscibility withfluorocarbon refrigerant.

Comparative Example 2

[0044] Tests were conducted to determine if compatibilizer could improveperformance during a retrofit from R22 and mineral oil to R407C (23 wt %HFC-32 and 25 wt % HFC-125, 52 wt % HFC-134a) and polyol ester (POE)oil. A ductless split R22 Sanyo heat pump (evaporator Model KHSO951,condenser Model CH0951) was installed in an environmental chamber. Theheat pump was outfitted with an R22 Sanyo rotary compressor (C-1R75H2R).The fan-coil unit was installed in the indoor room of an environmentalchamber and the outdoor unit was installed in the outdoor room. Thesystem was charged with about 1650 grams of R22 and 365 ml of 4GSmineral oil. Tests were conducted at ASHRAE cooling B conditions wherethe indoor room was controlled at 80° F. and 50% relative humidity, theoutdoor room at 82° F. and 40% relative humidity. Air side capacity,energy efficiency ratio (EER) measurements and oil volume measurementswere made. The system was then retrofitted by removing R22 refrigerantand 4GS oil without flushing, then charging the system with 1586 gramsR407C and 365 ml Emkarate POE RL68H oil (POE 68). Again, cooling Bmeasurements were made, then the test repeated retrofitting with R407Cand 365 ml Emkarate POE RL68H containing 20 wt % n-ocytylpyrrolidin-2-one. After each test, oil volume removed from the sump wasmeasured to assess oil return. Results are shown below.

Example 2

[0045] Cooling Test Sump Oil Volume After Test Capacity Oil CompositionTest (ml) (Kbtu/H) EER R22/4GS 320 8.72 10.58 R407C/POE 68 270 8.59 9.97R407C/POE 68 with 20% n- 310 8.59 10.05 octyl pyrrolidin-2-one andincluding residual 4GS oil

[0046] Results show significantly improved oil return, increased energyefficiency and equivalent capacity when compatibilizer is added to POEduring a retrofit from R22 and mineral oil to R407C and POE withoutflushing to remove residual mineral oil.

What is claimed is: 1.) A refrigerant composition comprising: (a) atleast one fluorocarbon; (b) at least one oxygenated lubricant selectedfrom the group consisting of polyol esters, polyalkylene glycols andpolyvinyl ethers; (c) at least one non-oxygenated lubricant selectedfrom the group consisting of paraffins, napthenes, aromatics andpoly-α-olefins; and (d) at least one compatibilizer comprising at leastone lactone selected from the group represented by formulas I, II, andIII:

wherein, R₁ through R₈ are independently selected from hydrogen, linear,branched, cyclic, bicyclic, saturated and unsaturated hydrocarbylradicals; the carbon to ester functional group carbonyl oxygen ratio isfrom about 7 to about 15; and the molecular weight is from about 100 toabout 300 atomic mass units. 2.) A method for replacing a firstrefrigerant composition comprising a chlorofluorocarbon and/orhydrochlorofluorocarbon and a non-oxygenated lubricant with a secondrefrigerant composition comprising a fluorocarbon and an oxygenatedlubricant in a compression refrigeration system without removingresidual non-oxygenated lubricant from said system, said methodcomprising: (a) removing essentially all said first composition from thesystem; (b) leaving residual non-oxygenated lubricant in said systemfollowing said removing; and (c) adding to said system said secondcomposition and a compatibilizer, wherein said compatibilizer comprisesat least one lactone selected from the group represented by formulas I,II, and III:

wherein, R₁ through R₈ are independently selected from hydrogen, linear,branched, cyclic, bicyclic, saturated and unsaturated hydrocarbylradicals; the carbon to ester functional group carbonyl oxygen ratio isfrom about 7 to about 15; and the molecular weight is from about 100 toabout 300 atomic mass units. 3.) A method for dissolving non-oxygenatedlubricant in a fluorocarbon and oxygenated lubricant refrigerantcomposition in a compression refrigeration system wherein saidnon-oxygenated lubricant remains in said system following retrofit ofsaid system from a first refrigerant composition comprising achlorofluorocarbon or hydrochlorofluorocarbon and a non-oxygenatedlubricant to a second refrigerant composition comprising a fluorocarbonand an oxygenated lubricant, said method comprising adding acompatibilizer to the system, wherein said compatibilizer comprises atleast one lactone selected from the group represented by formulas I, II,and III:

wherein, R₁ through R₈ are independently selected from hydrogen, linear,branched, cyclic, bicyclic, saturated and unsaturated hydrocarbylradicals; the carbon to ester functional group carbonyl oxygen ratio isfrom about 7 to about 15; and the molecular weight is from about 100 toabout 300 atomic mass units. 4.) The method according to claim 2 or 3,wherein the non-oxygenated lubricant is selected from the groupconsisting of paraffins, napthenes, aromatics and poly-α-olefins. 5.)The method according to claim 2 or 3 wherein the oxygenated lubricant isselected from the group consisting of polyol esters, polyalkyleneglycols and polyvinyl ethers.